Nozzle and seat structure



Dc. 31, 1957 RING 2,817,884

NOZZLE AND SEAT STRUCTURE Filed Jan. 23, 1956 9 v 1 IINVENTORQ Li" 0 iLucIAN RING L-JL BY v

[:51] 7 ATTORNEYS United States Patent NOZZLE AND SEAT STRUCTURE LucianRing, Birmingham, Mich, assignor to Ring Aluminum'Development'Companyg.a corporation of Michigam- Application January 23, 1956, SeriaLNo.v560,793 r 17 Claims; (Cl-.'22 '68) invention; t relates to: die castingmachines and refers .more particularly to a. nozzle and: seat- 1structure fordie-casting-machines Die.casting-machinesof the presenttype comprise: a-

die -ficavity and -a. cylindenleading-z to the-die cavity for It isdesirable that the annular discharge end-ofithe nozzle :01; supply tubeengages :the: annular seat surrounding thedntalre. portcontinuously.throughout the full.- 360 thereof :torpreventthe. escape of casting.materialt and; w-hereethe: casting material is drawn into" the. cylinderby-vacut1m,.;totprovider a, seal; However, becauseaof; the.engagementtofithe=supply ttubewith: the intake, port of the cylinderthere is. the. dangen that excessivenheat twill: bewithdrawn from thesupplv tube' andas; a result. the' molten castinggmateriah may; tend:tossolidifiy in the? supply tube. andtplugiti; I

Witlr the.- foregoing1in= view, it is .amobject of? this, in:-' ventionto.- provideta/nozzle and: seati structureiwhicha will permit. :ofiiatight. sealing engagement,; yet. which t will knot result. :in.excessive i. heat. transfenfrom. the a supply. tube tothe cylindenAnother: objectnof. the I invention! is :to, provide i-a-rnoz-zle andseat structure which will also reduce to a minimunr on substantially-3eliminate.-. wean betwcen .the engaging surfacestof thenoz zleaand seatpOther objects of the inventionwill'become. apparent asathe followingdescription; proceeds, especially" when considered: zinrconnection. withthe accompanying drawing, wherein Figured is; a-ssemi-diagr-ammatic-side.elevationalview of: apparatus embodyinggthe inventionz.

Figure .2. is;a transverse.-sectional.view .of. theapparatus, taken.along-thesline .22'.on-Figure 1 Figure: :3: ism-an enlarged .viewpartlyin section, of 1 a2 portion-of. the apparatus.

2,817,884 Patented Dec. 31, .1957- casting material which may be, forexample,v of the:1ight-' weight nonferrous type; such asaluminumymagnesiunr or zinc, is introduced into the die caviti'esby an.injectioncylinder or cold chamber 24. The cold chamber-24cm securedtoplaten 101 and projects through it; and. through the fixed die part12;.having' its outer endi communicating with the die cavities;

Thebold chamber-is, in theform of an elongated tube which is formedwithza plurality of elongated-passages 26-?having tubesZSveX-tendinginto the-.passages' whichrare connected to coolant-pipes 30; Thepassages -26: extend from the inner end332mofthe cold chamber toacp'oint adjacent the outenend Band the tubes terminate: short of theouter ends 'of-T the passages and are of substantially less. diameterthan "the "passages to' provide a return for thecoolin'g medium:introduced into thetubes 28 by the pipes. =30." Tfh'e coolant iswithdrawn 'from' the return .byi discharge-pipeswfls. By this means; thecold chamber 26 is-maintained=fatra uniform relatively cool'temperature;

A plunger: 364s.- supported forr sliding movement within the tubularcoldchamber A rodr38 has one end con nected towtheplunger- 36'andstheother end may be attached to: any zsuitablet mechanism(not-shown) for reciprocating the plunger-36*within' the cold chamber.

The: cold: chamberhasan" intake opening or port 40 through itsbottomwallwhich is spaced inwardly from the. discharge .or-outer end 42.Afrusto-conical seat 43 extendsdownwardly-from port 40; Theseat forms anangle of- 45 to the axis of thecone' which extends at right anglesto'the axis of the cold chamber. Seat"43 and. in fact the entirercoldchamber 24 is formed? of air-'- hardened' steel;- Moltencastingmateria'l forced into the diecavities by;plunger; 36 is initiallyintroduced intothe. cold: chamber through the intake opening:Therplungen 36"is reciproeable between aninner" position illustratedincFigures 1 and 3 at theinner side of the intake opening and ana outerposition located outwardlyxbeyond' the. in-' take opening.

As seenin 'Figure 1; a container or reservoir '4'4 is locatedbeneaththeintake opening'and-is adapted" to com-- tain a supply of moltencastingszmat'eriala46i' The-con Figure:4isanenlargedafr-ag-mentanydetaiL of a portion-of Figure};

1 Eignreriis a fragmentary-detail view.

Referring nowr more particularly to the -drawing the machinecomprises.astationary supportnor platen 10;

having-,a stationary die -pant 1-2-.'secured.'thereto'.- A-mow tamer-maybe heated :by any suitable means to: maintain-v the-casting materialin-aa'molten condition:

A vertical supply tube'or nozzle--48 is "provided for delivering: moltencasting material from the: reservoir into the intake. openinga-40ofthecoldzchamber. Theisupply tube is formed of tungsten carbide with acobalt binder; Alternativelythe supply tube may be formed-ofa ceramicmaterial; the principal constituent of which is carborundunr (siliconcarbide); with; a-suitable binder such" as' silicon nitride. The supplytube includesia: tubular. cylindrical portion 50; thelower end portion:of which extends be neath the top surfaceof casting material in thereservoir." The: cylindrical portion ofthesupply tube has-a "portion- 52adjacent theupper end thereof reduced in diameter for attachment to asupportingmember 54-. As shown: in: Figure 5 the opposite sides 5630fthe reduced portion 52Zare flattened to enable insertion of the reduced;portiom into a narrow slot 58 formed insthe supporting member54-andropening through one edge-thereof; The slot. 58 terminates in anenlarged portion which enablesrotating the tube- 48 m lock the same in'assembled relationshipwith the supporting? member 54.

Thesupporting member 54 is connected by vertical rods 60 to-acrossbar-62 positioned above the cold cham-= her- 24. Theupper-ends of.the vertical rods are'reduced toextend th'roughopenings formed in thecross bar 625;: The upper'extremiti'es of the reduced portionsof'rods-60 are threaded-and abutments 64 are secured to the-upperextremities of the rod's; Coil springs 66-= are mounted on: the reducedportions of the 'rods*- between the abutments and the cross bar. Thecross bar 62 is slidable on the reduced portions and the purpose of thesprings is to cushion engagement of the supply tube with the seatsurrounding the intake port to the cold chamber upon upward movement ofthe cross bar.

The cross bar 62 is connected to a hydraulic motor 68 comprising avertically extending cylinder 70 having a piston (not shown) connectedby a rod 72 to the cross bar. Cylinder 70 is mounted on bracket 73carried by support 10. Thus, vertical movement of the piston in cylinder70 imparts a corresponding movement to the cross bar to move the supplytube vertically along its axis.

A bearing block 74 is formed with a vertically elongated longitudinallyextending opening 76 for receiving the cold chamber 24. The lower end ofthe opening is shaped to provide an extended bearing contact with theadjacent outer surfaces of the cold chamber and the latter surfaces aremaintained in contact with the block by set screws 78 threadedlysupported in the block in positions to extend into the opening 76 andengage the cold chamber 24. The bottom of the block 74 is slotted toprovide a clearance opening 80 directly opposite the intake port 40 tothe cold chamber. The vertical rods 60 are respectively slidablyreceived in vertical grooves 82 formed in the bearing block at oppositesides thereof.

The supply tube is of one-piece construction and has an integral nozzleportion 84 at the upper end. The upper end of the nozzle portionterminates in a flat annular surface 86 which extends at right angles tothe longitudinal axis of the supply tube. The laterally outer surface 88of the nozzle portion 84 is frusto-conical, its axis coinciding with thesupply tube axis, and forms. an angle of 15 with the longitudinal axisof the supply tube. The laterally outer surface 88 and the end surface86 are connected by an annular surface 90 which is of convex arcuatecross section in planes through and including the longitudinal axis ofthe supply tube. The radius of curvature of the annular surface shouldbe between one sixty-fourth of an inch ,4; and three-sixteenths of aninch i In the present instance, such radius is one-eighth of an inch43"). The axis of the supply tube and of the surface 88 coincides withthat of the seat 43.

The convex annular surface 90 is adapted to sealingly engage with theconical seat 43 continuously throughout the full 360 thereof when thesupply tube is raised to the position shown in Figure 2. It is highlydesirable for such a sealing engagement to result in order to preventcasting material from leaking at the intake opening and also to maintaina vacuum within the cold chamber where the charge of molten castingmaterial is introduced thereinto by vacuum.

The supply tube is held against the seat 43 of the cold chamber under asubstantial pressure and therefore the annular surface 90 is rounded orconvex for engagement with the frusto-conical seat. However, the radiusof curvature should not be greater than of an inch in order to preventthe excessive transfer of heat from the supply tube to the relativelycool cold chamber. If a larger radius is employed, too great an area ofsurface-tosurface contact will result and the supply tube will be cooledexcessively. If the supply tube is cooled excessively there is atendency for the molten casting material to solidify therewithin andplug it.

If the radius of curvature of the surface 90 is too small, it will tendto coin or wear away the conical seat. Either of the materials specifiedfor the supply tube is harder than the steel seat so that the supplytube nozzle will not wear. To prevent wear of the seat, it has beenfound that the radius of curvature of surface 90 should not be less than,6 of an inch. If the seat 43 is coined by the nozzle portion of thesupply tube, then the area of surface-to surface contact would increaseand likely cool the supply tube excessively. Then, too, if the seat 43is coined, the seal between the nozzle and seat would no doubt be brokenor at least reduced in effectiveness. The ideal radius of curvature, allof the above factors considered, is A; of an inch.

The manner in which the molten casting material is moved through thesupply tube into the cold chamber may vary and forms no part of thisinvention and hence is not shown. Thus, when the piston is retracted tothe Figure 3 position, the casting material may be forcibly pumpedthrough the supply tube. On the other hand, vacuum producing equipmentmay be connected with the cold chamber to, in effect, suck the castingmaterial into the cold chamber when the piston is retracted to theposition illustrated. The piston is thereafter moved outwardly beyondthe intake port to force the casting material into the die cavities.

What I claim as my invention is:

1. In die casting apparatus including a die cavity and means providing apassage leading to said die cavity for introducing a charge of moltencasting material thereinto, an intake port to said passage, a supplytube for delivering molten casting material to said passage throu h saidintake port, an annular seating surface surrounding said intake port,said supply tube including a nozzle portion at the discharge end thereofhaving an annular surface sealingly engageable with said seating surfacecontinuously throughout the full 360 thereof, one of said surfaces beingfrusto-conical and the other being of convex arcuate cross-section inplanes through and including the axis thereof, the radius of curvatureof said convex surface being within the range of of an inch to of aninch.

2. In die casting apparatus including a die cavity and means providing apassage leading to said die cavity for introducing a charge of moltencasting material thereinto, an intake port to said passage, a supplytube for delivering molten casting material to said passage through saidintake port, a frust0-conical seat surrounding said intake port, saidsupply tube including a nozzle portion at the discharge end thereofhaving an annular surface sealingly engageable with said frusto-conicalseat continuously throughout the full360 thereof, said annular surfacebeing of convex arcuate cross-section in planes through and includingthe axis thereof, the radius of curvature of said annular surface beingwithin the range of th of an inch to of an inch, said supply tube beingmovable toward and away from said intake port to relatively move saidsurface into and out of sealing engagement with said seat.

3. The apparatus defined in claim 2 in which said nozzle portion isformed of a material including tungsten carbide and said seat is formedof steel.

4. The apparatus defined in claim 2 in which said nozzle is formed of aceramic material including silicon carbide, and said seat is formed ofsteel.

5. The apparatus defined in claim 2 in which the radius of curvature ofsaid annular surface is ;{;th of an inch.

6. In die casting apparatus including a die cavity and means providing apassage leading to said die cavity for introducing a charge of moltencasting material thereinto, an intake port to said passage, a supplytube for delivering molten casting material to said passage through saidintake port, a frusto-conical seat surrounding said intake port, saidsupply tube including a nozzle portion at the discharge end thereofhaving an annular surface sealingly engageable with said frusto-conicalseat continuously throughout the full 360 thereof, said annular surfacebeing of convex arcuate cross-section in planes through and includingthe axis thereof, the radius of curvature of said annular surface beingwithin the range of ,4 of an inch to 7 of an inch, said supply tubebeing movable toward and away from said intake port to relatively movesaid surface into and out of sealing engagement with said seat, saidsupply tube being formed of tungsten carbide with a cobalt binder andsaid seat being formed of air-hardened steel.

7. The apparatus defined in claim. 6 in which the radius of curvature ofsaid annular surface is of an 1116 8. In die casting apparatus includinga die cavity and means providing a passage leading to said die cavityfor introducing a charge of molten casting material thereinto, an intakeport to said passage, a supply tube for delivering molten castingmaterial to said passage through said intake port, a frusto-conical seatsurrounding said intake port, said supply tube including a nozzleportion at the discharge end thereof having an annular surface sealinglyengageable with said frusto-conical seat continuously throughout thefull 360 thereof, said annular surface being of convex arcuatecross-section in planes through and including the axis thereof, theradius of curvature of said annular surface being within the range of ofan inch to A of an inch, said supply tube being movable toward and awayfrom said intake port to relatively move said surface into and out ofsealing engagement with said seat, said supply tube being formed of aceramic material including silicon carbide, and said seat being formedof air-hardened steel.

9. The apparatus defined in claim 8 in which the radius of curvature ofsaid annular surface is $4, of an inch.

10. The apparatus defined in claim 9 in which said frusto-conical seattapers at an angle of 45 to its axis.

11. The apparatus as defined in claim 7 in which said frusto-conicalseat tapers at an angle of 45 to its axis.

12. In die casting apparatus including a die cavity and means providinga passage for molten casting material to be introduced into said diecavity, an intake port to said passage, a supply tube for deliveringmolten casting material to said passage through said intake port, anannular seating surface surrounding said intake port, said supply tubeincluding a nozzle portion at the discharge end thereof having anannular surface sealingly engageable with said seating surfacecontinuously throughout the full 360' thereof, one of said surfacesbeing of convex arcuate cross section in planes through and includingthe axis thereof, the radius of curvature of said convex surface beingwithin the range of ,4, of an inch to A of an inch.

13. The apparatus defined in claim 12 in which one of said surfaces isharder than the other.

14. The apparatus defined in claim 12 in which the convex annularsurface is harder than the other surface.

15. In die casting apparatus including a die cavity and means providinga passage leading to said die cavity for introducing a charge of moltencasting material thereinto, an intake port to said passage, a supplytube for delivering molten casting material to said passage through saidintake port, an annular seat surrounding said intake port, said supplytube including a nozzle portion at the discharge end thereof having anannular surface sealingly engageable with said seat continuouslythroughout the full 360 thereof, said annular surface being of convexarcuate cross-section in planes through and including the axis thereof,the radius of curvature of said annular surface being within the rangeof of an inch to of an inch.

16. The apparatus defined in claim 15 in which said annular surface isharder than said annular seat.

17. In die casting apparatus including a die cavity and means providinga passage leading to said die cavity for introducing a charge of moltencasting material thereinto, an intake port to said passage, a supplytube for delivering molten casting material to said passage through saidintake port, a frusto-conical seat surrounding said intake port, saidsupply tube including a nozzle portion at the discharge end thereofhaving an annular surface sealingly engageable with said frusto-conicalseat continuously throughout the full 360 thereof, said annular surfacebeing of convex arcuate cross-section in planes through and includingthe axis thereof, the radius of curvature of said annular surface beingwithin the range of ,4, of an inch to A of an inch, said annular surfacebeing harder than said seat.

References Cited in the file of this patent UNITED STATES PATENTS1,346,077 Carter July 6, 1920 2,084,349 Laise June 22, 1937 2,120,562Laise June 14, 1938 2,145,553 Morin Jan. 31, 1939 2,195,360 Daesen Mar.26, 1940 2,618,565 Nicholson Nov. 18, 1952 2,636,825 Nicholson Apr. 28,1953 2,708,298 Beckes May 17, 1955 FOREIGN PATENTS 716,842 Great BritainOct. 13, 1954

